Géraldine Duthé and Valérie Golaz

INED researchers Géraldine Duthé and Valérie Golaz explain how the world’s population is distributed, what demographic growth is expected in the coming decades, and present some longer-term demographic projections.

(interviewed in November 2022)

There are now 8 billion of us humans on earth. How are people distributed across the world today?

At this time, 6 in 10 of the world’s people live in Asia. China and India are the most populous countries, accounting together for nearly 3 billion people. But while China’s population has now stopped growing, the population of India continues to rise at a rate of +0.7% per year, meaning that India will have the most inhabitants by 2024. Africa is the second-most populous continent, accounting for nearly 20% of the world population. The African country with the largest population now is Nigeria, with 218 million. Thirteen percent (13%) of the world’s people live in the Americas, many in the United States (338 million), but the majority (8%) live in Latin America and the Caribbean. Fewer than one in ten human beings (9%) lives on the European continent, today characterized by negative demographic growth, whereas in 1950 Europe accounted for 22% of the world population. And a small proportion of the world population lives in Oceania (0.6%).

In addition to geographical distribution, it is interested to look at world population distribution the overall income level of residence country. If we follow the World Bank classification, three-quarters of the world population live in middle-income countries (74%); only 16% live in wealthy countries; and nearly 1 in 10 people live in low-income countries. Given that demographic growth is concentrated in this last group (+2.7% per year on average at the present time), we can say that the proportion of the world population living in poor countries has been rising since the end of the World War II: whereas in 1950 it stood at 5%, by 2050 it could well reach 15%. 

What is expected in the way of demographic growth in the coming decades?

The world population is now growing annually at a rate of 0.8%. That rate has been falling regularly since the 1970s. The United Nations currently predicts that world population growth will stop at around 2080. However, as we have seen, growth will not be equally distributed across countries and continents, and the relative demographic weights of the world’s regions will result in a major transformation of worldwide geopolitical equilibria.  

The populations of some countries, especially in Eastern Europe and Southeast Asia, are falling. The world’s strongest demographic growth is concentrated in Africa (+2.3% annually) and is due to that continent’s still relatively high fertility rate (4.2 children per woman on average), particularly in Central and West Africa. By 2050, Africa should account for 25% of the world population. 

Concernant les projections au-delà de trente ans par contre, qu’en est-il des hypothèses et de leur degré de précision ?

Demographic projections can be fairly realistic for 20 to 30 years into the future; knowing the age structure of existing populations means that numbers of deaths and births are predictable since women who will have children in the near future have already been born. But what about hypotheses or projections that go beyond 30 years? How accurate can they be? 

Although we don’t have exhaustive regular sources of information on global South countries, we do know fairly well how to estimate the current world population and it size in the coming decades. There can be offsetting events that are difficult to anticipate, of course, but we can still use past trends to project upcoming changes—namely in fertility and mortality. However, the further into the future we venture, the more uncertain our projections become. Fertility trends are what will determine world population dynamics, and those trends continue to surprise researchers. First, fertility is not falling as fast as expected in certain regions of the world; second, in many countries it has fallen below the population replacement level of 2.1 children per woman. 

The United Nations provides a range of estimates, including a medium scenario that falls between high and low estimates based on distinct fertility trends: plus or minus 0.5 children per woman on average compared to the medium scenario. This has led the UN to project a stabilizing of the world population at around 10.4 billion around 2080. But this relatively probable scenario is not the only one put forward. The more extreme ones predict stabilization at around 9 billion as early as 2050 or, on the contrary, continued growth to over 14 billion around 2100.